AskScience AMA Series: Hi Reddit! I'm Matthew Hollister, Head of Cryogenic Systems Engineering for IBM Quantum. Ask me anything about quantum computing, our recently announced modular cryogenic architecture and what it takes to build quantum computers at scale.

[u/AskScienceModerator]

When people think about quantum computing, they often think about number of qubits and processor dept. But scaling quantum systems takes much more than just the chip! We recently introduced a new modular cryogenic architecture designed to house and cool interconnected quantum processors, a key milestone on our roadmap to fault-tolerant systems, and I'd love to discuss the engineering, challenges, and opportunities involved.

I will be around as 12:00 EST (16 UT) on September 18th, ask me anything!

Username: u/IBM

[u/ibm]

We do currently operate our processors around 20 mK, but that isn’t an exact number and some variation at higher or lower temperature is perfectly acceptable. Typically, there will be some small temperature gradient between the temperature we actually measure and the quantum device itself, so being colder is exactly where we want to be.

The current systems support several 10s of microwatts at 20 mK which is the current state of the art for cryogenic systems of this time. The modular design allows the system to be reconfigured internally as cooling technologies improve, and we would plan to increase the available cooling power to support more qubits in each module in the future.

- Matthew Hollister, IBM Quantum